The present invention relates generally, as indicated, to an automatic rail greasing apparatus and, more particularly, to such an apparatus that dispenses metered quantities of lubricant directly to the work surface of a rail in response to the number of wheels or the like passing on such rail.
In modern railroad yards in which the cars of one or more trains are divided to make up several other trains, there is a hump located at a high elevation relative to other parts of the yard. At the hump there may be, for example, two main tracks which divide many times while passing in a descending direction in the yard, for example, to form sixty or more classification tracks, as is, of course, well known.
Ordinarily the larger the number of classification tracks, the sharper are the curves in the tracks that a car must follow as it descends down the hump to the lower classification levels in the yard. It has been found that as the curves increase in sharpness, the number of cars that jump the track or derail also increases. However, slowing the cars reduces the overall efficiency of the yard and, therefore, is undesirable. Also, slowing the cars too much as they approach the area of coupling with another car, say near the end of a classification track, may prevent the car from reaching the intended end of its run to effect such coupling.
One technique for improving safety in railroad yards, i.e. by reducing the number of derailments, has been to reduce the speed of the cars as they come down the hump, either by reducing the angle of the slope of the hump or by increasing the number of mechanical retarders or the amount of retardation effected by existing retarders that slow the cars as they come down the hump.
One reason for such derailments has been found to be the relative inability of the railroad car wheels to slide laterally on the tracks as they pass on a curve. Therefore, one technique used in the past to facilitate such lateral sliding has been to form a long, for example six feet or so, groove in the top crown or work surface of the head of the rail, which is supported by the web and the base of the rail, and to pump oil, which is relatively non-viscous into the groove to lubricate the wheels passing thereover. There are a number of disadvantages with such a system, though. For example, the relatively light weight and non-viscous oil has been found to pour over the rail or to be picked up and blown by wind with the result in either case being a polluting of the local environment, including possibly destruction of vegetation and/or polluting of water in adjacent drainage ditches. Moreover, the grooves in the rail may encounter blockages, for example from dirt, ice, or other obstructions, thus making them relatively ineffective to lubricate wheels passing thereover.
The inability of a train wheel to slide on the top surface of a rail head as it passes on a curved track section, and especially on the so-called low-side rail, may cause extremely large forces on the rail, on the one hand, possibly destroying the rail, on the other hand, adversely slowing the car. This slowing effect may vary with weather conditions, e.g. a wet rail will not slow a car as much as a dry one, and such unpredictability of rail-wheel friction coefficient, then, requires, undesirably, excessively subjective control of retarders in a yard or train operation on a line. It is, accordingly, desirable to predictably improve and maintain the rollability of train cars and wheels thereof particularly on non-linear track sections.